Integrative and functional medicine doctors have been talking about vitamin D deficiency—and its many health consequences, including a weakened immune system and low mood—for years. And now, the rest of the world seems to be catching up—starting with England and Wales.

According to new research from the University of Birmingham, England and Wales have a plan to combat the ever-growing vitamin D deficiency epidemic by adding the vitamin to wheat flour. The research, which was published in the European Journal of Clinical Nutrition, showed that requiring mandatory fortification of vitamin D in wheat flour would prevent 10 million new cases of vitamin D deficiency—and save the country a lot of money down the line. How much money exactly? They estimate around 65 million euro, which is a little over 72 million U.S. dollars.

But is "epidemic" really the right word to use? How big is the vitamin D problem, really? In the U.K., it's estimated that 20% of adults are deficient in this essential vitamin—and some think that number in the U.S. could be as high as 50%. The explanation for this is multifactorial and includes not eating enough vitamin-D-rich foods and sunscreen use and spending too much time indoors, which puts us at risk for deficiency because we're supposed to get the vast majority of our vitamin D from the sun.

If you're wondering why you can't just take a vitamin D supplement, you're not alone. But according to the lead author on the study, Magda Aguiar, Ph.D., from a public health perspective, fortifying commonly eaten foods will be more effective. "While both supplements and fortified foods are important sources of vitamin D for the U.K. population, evidence suggests current U.K. supplementation policies are not working," Aguiar explained.

This is particularly relevant to groups that are already at higher risk for vitamin D deficiency, including people who are obese, have darker skin, or who are 65 or older. As Aguiar said, "We now hope that U.K. policymakers will consider a new national policy to fortify foods such as wheat flour with vitamin D to address this serious health issue. This will lead to significant benefits for the population, particularly the most vulnerable groups."

The good news is that this same policy has worked before. Finland fortified all its breads with vitamin D and lowered the rate of deficiency from 13% to 0.6% of the adult population. So whether you're getting it from the sun, a supplement, or a loaf of bread, here's to fewer vitamin D deficiencies.